Abstract
Isolated chloro-plasts from enucleated, bacteria-free Acetabularia cells were found to contain DNA in the approximate ratio of protein to DNA of 5,000 1. DNA was determined by the specific fluorometric procedure of Kissane and Robins before and after hydrolysis with DNAase. Centrifugation in a density gradient showed that the distribution of DNA paralleled the distribution of the chloroplasts, indicating that the DNA was either associated closely with the plastids or was a part of them.